The present invention relates to shampoo compositions, and more particularly to shampoo compositions containing highly viscous silicones which are preferably silicone resinsor siloxane gums, giving body to fine, limp hair and increasing the ability of hair to hold a style.
The property of hair known as "body" is a complex one, and can be interpreted as fullness or volume of the hair. It also embraces ease of styling and ability to hold a style. Fine hair often suffers from a lack of body and is found to be limp and unmanageable.
Other types of hair can benefit from an increased ease of styling and an increased ability to hold a style. Generally, this is achieved by application of film-forming materials to the hair, usually after shampooing and/or conditioning in the form of mousses, gels or sprays.
Silicone materials have been applied to the hair to give some conditioning benefit, see for example U.S. Pat. No. 3 964 500 and U.S. Pat. No.4 364 837. However, the silicones used are generally of relatively low viscosity since low viscosity silicones are more readily incorporated into shampoo compositions.
Highly viscous silicones have the ability to modify the condition and manageability of hair. Siloxane gums improve the combability, softness and condition of the hair and reduce its susceptibility to damage due to mechanical manipulation caused for example by brushing and styling. Silicone resins give body to fine, limp hair and increase the ability of hair to hold a style.
These highly viscous silicones are extremely difficult to incorporate into a shampoo product, because they cannot be dispersed to form droplets or an emulsion. To aid dispersion, the highly viscous silicones must be first dissolved in a volatile solvent in order that the viscosity be reduced. The solution of the highly viscous silicone may then be emulsified.
In JP 61/161214 (Shiseido), setting compositions comprising silicone resin and volatile silicone are disclosed. These compositions are delivered from both leave-on and rinse-off compositions containing volatile solvents which evaporate to leave the silicone resin on the hair.
EP 240 350 (Procter & Gamble) relates to compositions comprising a rigid silicone polymer and a volatile carrier.
The droplets of silicone polymer in volatile silicone, obtained by the process used in EP 240 350 are in general greater than 5 .mu.m in diameter on average. Such relatively large particles are more difficult to suspend in a shampoo system, and can give rise to processing difficulties with the need for hot processing and high shear mixing.
Particles having an average diameter of less than 2 .mu.m tend to remain suspended in a shampoo composition and are therefore rinsed from the hair. We have found however that by including a cationic derivative of guar gum in the shampoo composition, small particles, i.e. those having an average diameter of less than 2 .mu.m, can be effectively deposited on the hair shaft.